cull
An individual animal selected to be killed, or item of produce to be discarded.
cull: livestock or crop deemed unfit to keep or sell
A cull is an animal removed from a herd or flock for slaughter, or produce rejected during grading and removed from the sale lot. The animal or item fails to meet the standard set for the commercial operation, whether due to age, injury, disease, poor conformation, low productivity, or quality defects. In livestock, culls are typically sorted at the point of sale or during routine herd management; in produce, they are separated during harvest, washing, or packing operations.
In dairy herds, culls include cows past their productive peak, those with chronic mastitis or lameness, and animals with low butterfat or protein yields. Beef cattle culls are often older animals, those with poor growth rates, or breeding stock with genetic faults. In poultry operations, culls may be undersized birds, those with visible deformities, or hens no longer meeting laying quotas. The timing and criteria vary by species and production system.
Culling decisions and economic factors
Culling is a management tool tied directly to profitability. A dairy farmer culls a cow when the cost of her feed and care exceeds her milk revenue. An apple grower culls fruit smaller than 2.5 inches diameter or showing russetting or bruising, as these do not meet buyer specifications or market grade standards. The cull rate signals herd or crop health; unusually high culls may indicate disease, poor nutrition, or environmental stress.
Culled livestock enter a secondary market: dairy cows go to processing plants for ground beef, breeding stock may be sold at auction for other operations, and culled poultry becomes pet food or rendered product. Culled produce typically enters the waste stream, though some operations recover it for juice, animal feed, or compost. The economic value of a cull is lower than that of the primary product, sometimes negligible, making cull reduction a constant objective in efficient farming.
The term originates from the verb "cull," meaning to select or gather, used in hunting and foraging for centuries before becoming standardized in agricultural commerce. In modern usage, culling is both a noun describing the animal or item removed and a verb describing the act of removal and selection.